I found comments online about that though the maximum capacity of a DVD is 4.3GB, you should't burn it fully, but leave a small empty space. Is this correct? If yes, what is the recommended maximum amount I should burn?

4480mb is the max, but if your worried about recovery etc do 4096mb and use multipar to make recovery info. That way in the event of a error you can get your files back...usually. I do this with pretty much all the dics I author with 5-10% redundancy. Just writing less really does nothing as a scratch is well a scratch at the end of the day

I found comments online about that though the maximum capacity of a DVD is 4.3GB, you should't burn it fully, but leave a small empty space. Is this correct? If yes, what is the recommended maximum amount I should burn?

I have never had issues with how much gets burned. When I get the message (however worded) data is more than disk capacity, I remove the minimum amount to be under disk cap. I also set burn speed way below the disk advertised write speed.

Pretty much every DVD I ever encoded myself uses the capacity of the media by almost 100%. On a DVD+R I never come up with less than 4460 MiB out of the available 4482.25 MiB.

Never, in all those years, had problems with the last parts of the video skipping or so. I use Verbatim DVD+R AZO made in Taiwan (the Indian ones are way inferior, avoid those), and burn with my BenQ DW 1650 at half the rated media speed (usually 8x).

According to the Verbatim web site some DataLifePlus DVDs also use the AZO recording dye. Ive been buying 16x DVD+R 50 pack in the clear container for years and have had no problems. They have an 82% 5 star rating on Amazon. Made in Taiwan. Product #94917

All this discussion thus far has been centered on 4.7 GB DVD's. What is the consensus thought on DL 8.5 GB DVD's? An obvious cursory glance by a noobie such as myself thinks, "Perfect! Twice the storage!". But are they reliable? Or are they problematic?

All this discussion thus far has been centered on 4.7 GB DVD's. What is the consensus thought on DL 8.5 GB DVD's? An obvious cursory glance by a noobie such as myself thinks, "Perfect! Twice the storage!". But are they reliable? Or are they problematic?

You are unfortunately running into a discussion about ancient technology....well almost.
We may as well be discussing who makes the best blank audio cassettes....Maxell, TDK or BASF.

Databases and lengthy discussions about the best blank DVD manufacturers and brands have been abandoned years ago....now it's a crap shoot.
Just grab some Verbatim and hope for the best.